Within the licensed spectrum, increased data traffic has caused operators to consider alternative solutions by which at least some of the traffic is off-loaded to local nodes that provide local access to the Internet or other networks so as to reduce congestion of the core network. For example, femtocells operating in the licensed spectrum may service local nodes and may facilitate local access to the Internet or other networks. However, data traffic is anticipated to continue to increase and, as such, operators are continuing to seek other options for off-loading traffic from the core network.
In this regard, operators are considering utilization of the unlicensed spectrum (also referenced as the shared spectrum) in order to support at least some of the data traffic. While various shared bands have been defined within the unlicensed spectrum, examples include the industrial, scientific and medical (ISM) band and TV white spaces (TVWS). In order to coordinate spectrum usage, such as the usage of TV white spaces, a coexistence manager is being developed pursuant to IEEE 802.19.1. The coexistence manager is radio access technology (RAT) independent and is generally focused upon the coordination of spectrum usage among IEEE-based technologies over transmission control protocol (TCP)/Internet Protocol (IP) interfaces. As a result of its RAT independence, the coexistence manager is a scalable solution and can correspondingly interwork with a number of different systems. As such, the coexistence manager may serve as a relatively high level coordinator that may facilitate the negotiation between RATs regarding spectrum utilization or may govern the spectrum utilization for the shared spectrum locally. A coexistence manager may operate in a relatively large time scale, that is, the reaction time of the coexistence manager to interference issues between systems is substantially greater than the time quantities of the physical layers of the systems. It may therefore be desirable to provide for smaller time scale coordination between the systems that are being coordinated by the coexistence manager.
From the long-term evolution (LTE) perspective, LTE access points, such as evolved Node Bs (eNBs), may operate in the unlicensed spectrum. As a result of their capability to manage deployment bandwidth and the number of utilized carriers and to permit flexible reconfiguration of the center frequency, LTE may offer advantages for operation within the unlicensed spectrum relative to compliance with IEEE 802.11 standards.
LTE supports radio access network sharing as a result of its support for multi-to-multirelationships between evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) nodes and evolved packet core (EPC) nodes. In this regard, the network sharing architecture supported by LTE allows different core network operators to connect to a shared radio access network. The operators not only share the radio network elements, but may also share the radio resources themselves. In addition to the shared radio access network, the operators may optionally have additional dedicated radio access networks, such as a second generation (2G) radio access network.
As a result of the advantages offered by LTE systems and the operability of LTE access points within the unlicensed spectrum, it may be desirable to improve the coordination between LTE systems, such as the smaller time scale coordination between the LTE systems, in order to leverage those advantages. Moreover, it may be desirable to improve the coordination between LTE systems that is provided by a coexistence manager.